Is There a Shortcut for Creating a Surface from Multiple Nurbs Curves

[Phillip Tripp]

Objects on left in image below are all nurbs curves.  Outer squares are higher elevation and smaller square is central drain at lower elevation.  I know I can use the loft command to create a surface from the one large outer square to a small central square creating an upside down pyramid surface.  Is there a command that would allow me to convert all the nurbs curves to a surface in one operation, rather than going through each 2 object area one at a time?  The image on the right is the goal, a surface (shown in wireframe).

 

[Benson Shaw]

Lots of ways. Here are a few
1. Make one cell and duplicate it for the other three:

Draw a small square and surrounding large square, convert to NURBS, ungroup, raise/lower the small one, loft>ruled, duplicate/mirror/move as needed to arrange the grid of 4 shown in your image. 
 

2. learn slab drainage, apply to a slab. 
 

3. Create a mesh from your 2d grid. Raise lower the small squares via the Select tool (not the Reshape tool).

 

-B

[VIRTUALENVIRONS]

Hi Phillip,

Are you asking if you can do all four at once?

[Phillip Tripp]

2 hours ago, VIRTUALENVIRONS said:

Hi Phillip,

Are you asking if you can do all four at once?

Yes.  All at once.  The grid was only an example layout.  If it was an actual grid, we'd copy and paste and be done.  The real world example is made up of 100 unique shapes with a central low point in each shape.  Outer shape is not always 4 sided or regular.  The central low point is a 6 inch square and every low point will have the same elevation.  The outer shapes will all have the same elevation, but higher.  It is roof top slab drainage, but it is not our scope of work.  We were looking for a fast way to 3D illustrate the intent for checking for conflicts with surface pavement above the roof, rather than wait for a consultant to deliver their model.  I was hoping if we assigned z elevation to all the interior low points and assigned a z elevation to all the outer shape lines, there was a way to create a surface all at once for everything, rather than one shape at a time.  

[Phillip Tripp]

I modeled it one drain at a time.  To recap, was curious if there was a shortcut to do the entire roof top surface all at once.  

 

 

[VIRTUALENVIRONS]

HI Phillip,

I can't think of one using NURBS tools, but I may know of one using standard tools that could possibly cut your workload down significantly.  I will make a short video and upload this morning.

 

Paul

[VIRTUALENVIRONS]

Hi Phillip,

This method would work well with a rectangular building, concourse, etc., as in your first post.  It may only be partially applicable in your last post or perhaps not at all, but shows another dimension of modelling in Vectorworks.  It may help in the future.

 

This tutorial is done from a starting point of a 2D plan view

 

 

 

[bcd]

Select all>Convert to 3d Polys

Ungroup

Select all>AEC>Terrain>Site Model from Source Data

[Phillip Tripp]

Thank you both. We'll look into Paul's convert to mesh option.  We initially tried the terrain model option which was quick like expected, but it was successful for a short time.  The same file had a site model within inches vertically of the roof slab site model and several walking surface grade tool options which all competed for claiming a z elevation at coincident points in space which quickly led to issues even if we assigned only limited design layers to each site model.  This is an older large project in VW2022.  We cleaned the file up but wanted to keep the roof slab as separate 3D object rather than another site model given the issues we were seeing in the file.

[bcd]

You can ungroup the site model in 3d and deleted Site Model Opacity Container - you'll be left with the Mesh.

 

Edited December 11, 2024 by bcd

[VIRTUALENVIRONS]

As this began with a NURBS question, I dialled into that, but I have used the terrain modeller in the past for situations like this.  I did find limitations, but not sure whether they were the program's or mine.

 

The solution may be a combination of several methods.

[Phillip Tripp]

thanks BCD.  if my memory is right, i did try the mesh from site model, but it was early test using poorly constructed lines from a consultant for the roof model, so it was a bad site model result on our end due to gaps between lines.  when i get a free moment, i'll probably do a quick test of the options to see what's fastest, all starting from good line work.  the good news is the quick model helped convey clash points and helped bump the urgency of team coordination.

 

i appreciate the continued feedback!

[bcd]

Cool @Phillip Tripp I'm glad to hear it was helpful.

 

[Phillip Tripp]

Paul, is there a method to split the nurbs surface into each drain area when the drain areas are not arranged in a grid, for conditions when use of a straight line split tool doesn't work?  The workaround I used was rather than using the ridge lines as guides for the split tool, I used them as boundaries for the polygon fill tool, then used those fills with the extract surface method to get individual nurbs surfaces.  This method works fine and is faster than the loft method.  If I had to guess, the site model method would be fastest if geometry is clean to start with.

 

[VIRTUALENVIRONS]

Yes, different process.  Give me a little time.

 

Paul

[VIRTUALENVIRONS]

@Phillip Tripp  This method might work better even for a square roof. 

 

Paul

 

[Phillip Tripp]

Thanks for the quick follow up!